In recent years, power line communication (hereinafter also referred to as “PLC”) that performs communication by superimposing information on a power line has been proposed. This is a technique that uses a power line as a wired communication line by attaching a modem that superimposes information on the power line to the power line. By using a power line as a communication line, it is possible to reduce a large number of wires in a wired communication system that requires a normal power line and a communication line.
On the other hand, the PLC has a problem that other apparatuses are affected by superimposing information on a power source current. However, the PLC is useful in a closed environment where a power line is scheduled to be used as a communication line. For example, it is proposed to arrange a power line communication system in a closed space such as a marine vessel (Patent Literature 1). Further, it is also proposed to control lighting in one building by the PLC (Patent Literature 2).
In the PLC proposed in Patent Literatures 1 and 2, a unique address is provided to each terminal (an object to be communicated with) and information is transmitted and received by time-division multiplexing the information.